Fluid power steering gear for swinging axles



F. P. MARTIN FLUID POWER STEERING GEAR FOR SWINGING AXLES Jan. 8, 1952 5sheets-sheet 1 Filed March 28, 1949 nventor rlnilxlllw Gttomegs Jan. l8,1952 F, P, MARTIN 2,582,142

FLUID POWER STEERNG GEAR FOR SWINGING AXLES Filed March 28. 1949 5Sheets-Sheet 2 (Ittorneg I F. P. MARTIN Jan. 8, 1952 FLUID POWERSTEERINGIGEAR FOR SWINGING AXLES 5 Sheets-Sheet 5 .Filed March 28, 1949Snuentor @ed Mar/927 ffy Gttornegs Jan. 8, 1952 F. P. MARTIN FLUID POWERSTEERING GEAR FOR SWINGING AXLES Filed' Maron 28, 194.9

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. \J. w S l v n NW an |7| an W sm. .U m E l .WN Qm, Q NY Bnnentor P., dn? Gttornegs Jan 8, 1952 F. P. MARTIN FLUID POWER STEERING GEAR FORSWINGING XLES 5 Sheets-Sheet 5 Filed March 28. 1949 yPatented `lari. 8.,1952 fi-i oFF-ics t 'FLUIDPOWER-fsTEERmG GEAR Fon :SWINGING AxLEs Fred.'P. Martin, Topeka, Kans.

'Application'Marcli l28, 1949, Serial No. 83,914 l This inventionrelates 'to power 'operated'- vehicles suchas tractors havingY multipleyaxles-fand more particularly to such' a lvehicleV in .whichdriving'power yis delivered'l from` the engine vto all of the 'roadengaging wheels and' an axle turned by power for steering, saidinventionbeing' adapted `for useon wheels having a driving axle andmounting for turning of same l for steering such' as is disclosed inmy'copending application, Serial'No;758,l5 1', filed June 30, 1947.

The objects' of thepresent invention are to provide an all4 wheel driventractor' wherein the@ power is transmitted through gear reduction-s andLconventional Idifferential structures which may be repairedandmaintained by thev ordinary=nie chanic; to provide an allvvheel`-d`rivenV vehicle giving increased traction and-pulling powerandhaving an axle turned by power for steering'v with increasedmaneuverability; to provide an hydraulicallyv driven gear reductionsteering mechanism for easy, safe and positive-controlA of the turningand positioning of the steering axle; to provide avehicle `with adriving 'ax-le' having limited universal or'swinging movement on vsaid*vehicle whereby the traction wheels'may assume different elevationsrelative` toA said vehicle in passing over uneven Yground-and lpermitthe Yaxle to be turned; to-'steerJ the vehicle; to provide a drivingaxle with spacedfsupporting connections on a vehicle, said connections.beingspace'dffrom said axleyandl at diiierent elevations` and; anglesfrom the axis .of said axle for pivoting thedrivzsaolaivmsf. f( c1.1mi-179.2.)y

ingv axle on the vehicle about -a vertical axis, one

of said supports including la series of oscillating rollers permittingswinging movement ofI said axle; to provide mechanism for transmittingpowerfrom the engine of the vehicle to a connection on the turntableaxle for turning same regardless ofthe elevation of'the'traction wheelsor other swinging and pivotal movement of said axle to provide limitcontrols for' limiting the turning movement of the steering axle; toprovide an all Wheel driven vehicle having an axleturned by power forsteering','said wheelsbeing driven through the combination ofdifferential structures betweenY the wheels and .between thedrives forthe"respectiveaxles; and 'to provide anA all wheel driven vehicle havingan axle turned-"foristeeringthat is capable of-easyy maneuvering, shortturning radius, `high traction efforts, flexibility ofA operation onalltypes of terrain, positive in steering lande'iiicient, sturdyandeconomical to operate and maintain.

In accomplishing thesef-andother objects of the'present invention,-Ihave provided improved 2, details offstructure; the preferred forms ofwhich are illustrated Iin the accompanying drawings, wherein:v i

`Fig.-1isa side elevation of avehicle embody--y ing the -features of`the present invention v*hav-- ing `the body and hood removed and'portions broken away to better illustrate the parts therein.

Fig. 2 isfa'plan view'orthechassis ofi the Atrac-v tor.'

Fig. 3 is -a'verticall sectional view on thefline 3-3, Fig. 4, lthroughthe oscillating'rollerr support for the front axle.

Fig. -4--is a vertical sectional .view on theilin 4 4, Fig. 3,illustrating thefpivota'Lmountingof' the oscillatable roller support.

Fig. '5 is a detailfsectional viewthrough--the- Fig; 7 'isffa horizontalsectional viewv through'4 the-forwardlendof the vehicle,par-ticular-lyil-- lustrating the axle connecting and supportingmembers; and axle-steering connection.

Fig.' 8 y is av verticalsectional vievv-A of the 1 frontaxle mounting,portions of 'said mounting, gear reduction andfdifferential 'gearingbeingu broken away-to better' illustrate the parts therein.

Fig; 9 isa perspective View*offthefpowersteer-- ing mechanism.

Fig. 10 isa vertical sectional view through the universal powerconnection on the* Asteering mechanism.

Fig-g 1--1 is a diagrammatic' viewlillustratingthe positionof the wheelsand axles when turned as in negotiatinga curve.

Fig; 152' is a'Y diagrammatic viewillustratingl the` valveandconnections Afor controlling operation of the power steering motor.

Fig. 13 is a sectional view through the iront axle -yoke showing themounting of the limit control Iear thereon.

ReferringL more in detail to' the drawings:

lI designates a'motorvehicle such as a tractor having a chassis 2supported on a plurality of. axles; In the form of the inventionillustrated thechassis consists'of a frame 3l carrying an 'engine 4preferablyin the forwardfportion thereof. The frame is supported on afront Vaxle housingi and rearv axlehousing 6, the axles being carriedbyr wheelsr'l and 8 respectively. The frame 3 consists of spaced channelAmembers 9 andl IIl)Y arranged longitudinally of the vehicle andconnectedff-adjacent l'their front and 'rear aseaiie ends by transversechannel members II and I2 respectively, the ends of which are suitablyconnected as by welding or the like to the longitudinal channel members,said longitudinal members also being connected by other transversemembers or suitable bracing to provide a rigid frame structure.

The axles and 6 conform to well known design of commercialautomobilje`or xtruck rear axles except for slight alterations and'additions asbecome necessary to adapt the same for the use herein exemplified. Nobrake mechanism is tional and forms no part of the invention.

Depending from the channel member I I 'and preferably centrally arrangedrelative to the longitudinal channels 9 and Ill is a ball member I3universally rotative in a spherical socket member I4 suitably secured tothe upper portion of an A-frame or yoke I5, saidv A-frame havingoutwardly andY downwardly directed legs I6 and I1, the lower ends ofwhich are provided with feet I8 adapted to rest on suitable pads I9mounted on the upper portion of the axle housing 5. The feet I8 aresecured to the axle housing and the pads I9 thereon by means of U-bolts26 engaging over the upper portion of the feet and having legs 2Iextending downwardly therefrom and through suitable'apertures in a plate22 extending under the axle housing 5, nuts being applied to the ends ofthe U-bolt legs for drawing the plate 22 into snug engagement with theaxial housing 5.

In order to stabilize the universal action of the front axle housingmounting and particularly to eliminate longitudinal movement of saidhousing relative to the vehicle, an arcuate member 23 is arrangedsubstantially in a plane at right angles to the vertical axis extendingthrough the ball and socket members I3 and I4. The arcuate member 23preferably consists of a heavy, fiat bar or other suitable structuralshape, bent in the form of a semicircle and having its ends secured asat 24 to the axle housing 5 by means of suitable U-bolts and platestructure similar to that for anchoring the A-frame or yoke I5 to saidhousing. The ends of the semicircular member 23 are preferably securedto the axle housing near the wheels 1 and extend to the rear of saidaxle housing 5 the arcuate member extending through a support structure25 which permits the arcuate member to move when the housing 5 is turnedabout a vertical axis and permits lateral oscillation of said axlehousing and arcuate member as when the wheels pass over uneven terrain.

' The support 25 preferably consists of a series or rollersl mounted onthe frame for oscillation about an axis perpendicular to the verticalaxis extending throughthe ball and socket members I3 and I4. Moreparticularly the support 25 consists of suitable rollers 26 and 21having rolling engagement with the upper and lower edges 28 and 29 ofthe -arcuate member 23 and rotatably mounted in spaced plates 30 and 3l,said plates being held in suitablyspaced relation by means of studs 32extending through apertures 33 in said plates and having nuts 34threaded on the ends of said studs to draw the plates together and intoengagement with suitable spacers 35 arranged on the studs between theplates. Each of the plates is provided with a boss 36 having suitableantifriction bearing 31 mounted in a bore in said boss, said bearings 31being mounted on'ends 38 of stub shafts 39 and 40, secured by means yof,U-bolts- 4I to the lower ends `42 of suitable bracing .43 carried onthe longitudinal frame members 9 and I9. The stub shafts 39 and 46 arepreferably arranged in parallel relation to the longitudinal center ofthe frame 3 whereby the bearings 31 permit rotative movement of theplates 30 and 3| in a vertical plane transversely arranged relative tothe vehicle frame 3.

This structure prevents upward or downward movement of the rear portionof the arcuate member23, thereby preventing movement of the axle housing5 longitudinally of the vehicle. It does provide for lateral movementsimultaneously l=with the turning movement of the axle housing about theball and socket members I3 and I4 and thereby providing for suitablemovement of the axle housing 5 when the wheels 1 pass over unevenground.

The axle housing 5 includes a differential gear housing 44 enclosingconventional differential gearing 45 operatively connected to axles 46and 41 extending through the axle housing 5 and operatively connectedwith the wheels 1. The differential gearing includes a conventional ringgear 48Vmeshing'with a beveled pinion 49 fixed on a driveshaft 59rotatably mounted in suitable bearings 5I carried in a verticallyarranged extension ofthe housing 44 whereby the shaft 59 is on avertical axis extending through the ball and socket members I3 and I4.The upper end of the shaft 5U carries a ring gear 52 enclosed in ahousing 53 which is supported on a bushing 54 by roller bearings 55,said bushing having a flange 56 secured by suitable fastening devicessuch as screws to the extension of the differential housing 44. V'Ihisstructure permits the housing 53 and the axle housing 5 to have relativerotation. The beveled gear 52 meshes with a beveled pinion 51 and anythrust imparted by the beveled pinion to the beveled gear is taken bythrust bearings 58 between the gear 52 and .the lower part of the gearhousing 53.

The beveled pinion 51 is mounted on a shaft 59 which is carried insuitable bearings in a housing extension 60 projecting rearwardly of thehousing 53 and arranged perpendicular to the axis of the shaft 50. Therear end of the shaft 59 is suitably connected to a drive shaft 6I bymeans of a suitable universal joint 62. The drive shaft 6I preferablyconsists of telescoping keyed members to provide extension andcontraction of the drive shaft 6 I. The rear end of the driveshaft 6I isconnected by a universal joint 63 with a shaltf64 extending forwardlyfrom adjacent the lower end of a housing 65 enclosing suitabletransmission mechanism such as chains, sprockets and gears operativelyengaged to receive driving power from the conventional transmissionenclosed in the housing 66 mounted on the rear of the engine 4, which issuitably supported on the frame members 9 and Ill as at 61. Thisarrangement connects the engine as later described with the differentialgearing in the axle housing 5 to deliver power thereto with the shaft-6Isubstantially horizontally arranged and in parallel relation with theframe members 9 and I0.

Since the axle housing 5 is rotatable about a verticalaxis extendingthrough the shaft 50 and is rotatable relative to the housing 53, saidhousing 53 may be held against rotation relative to the chassis by meansof a Wishbone connection 68 with the frame. Said Wishbone arrangementconsists of arms 69 and 1D, the forward ends of which are connected toears 1 I and 12 extending laterally of the housing-53 by means of balland socket devices. 1.3.- ',Ijhe arms 69 and 10 converge and-areconnected` `bysva collar I4 @slidable fand.

rotatable -von a shaft-;: therearend ofs-which is-connectedbyalball-andfrsocket connection 16 mountedon the lower end ofa bracket'I'I whichy is secured toltheirearmost brace '43.l The wishbonestructureV permits-free oscillatory movement of the `axle housing onthe-ball and socket members I3 and i4; but maintains thegear housing;

extension 69 substantially `in alignment with the shaft 64 of thetransmission housing-65.

The rear portions' of thelongitudinal frame members 9 and lareconnected-by the transverse' -member- I2 and -eachf of. `thelongitudinal.

members is provided Iwith :downwardly extendingsuitablyfbracedlegs 18,the-lowerrendsv of which are-secured to-the axle housing-6 :by platesand bolts l9 togrigidly xthe rear axlehousing 6 transversely Vof .theframel2.` Theaxle housing; 6 includes av-gea-r housing .80.for enclosing:suite able diiferential gearing: l substantially-.the same asconventional` automotive beveled geandiffere V entialstructure andthesame as the differential structure enclosed. in. the rhousing k44 of4the :front axlei housing. Thehousing 89 is providedwitha verticallyarrangedy extension 8| on which is4 secured a..housinglenclosing-abeveled gear.

having, meshing engagementy with.; a beveled pinion .in lthe same manneras.. the gear and beveledepinion inl the housing` 53,. said beveled.:

pinion being carried inzsuitable bearings in. a.

housing extension `33,.;arranged forwardly of the shaft 64, in!` thev.transmission housing 65,..V The shaft 84 is connected by means of auniversal joint coaxial with the shaft 64, lthe shaft188receiving powerfrom thetransmission-mechanism to de liver power of the engine tothediiferentialgearing in the houing 80 of rear axle housing, saiddifferential gearing being. connected in a conventional manner withthewheels` Bafor driving same and permitting said wheels to rotate atdiiferent speeds as w-henthevehicle is turning or negotiating an arcuatepath.

The housing is` suitably securedto the trans-` mission housing 66` and`encloses.V transmission mechanism as illustrated in.v Fig. 5, A drivenshaft' |56` extends from ,the` rearv of the transmission housing 66,'theend of said shaft being rotatably supported inA abeairng v89 carried inthe housing 65; Keyed to theA shaft 66." is a sprocket 89 havingdrivingy engagement with a chain'90 which engagesanddrives a sprocket 9|rotatably mountedin bearings 92 and 93 which rotatably mount the shafts64 'and' respectively. Carried by the sprocket 9| is a suitabledifferential Vvgearing 96`consisting of a spider 91 carrying beveledpinions 98 meshing with beveled gears Yligand |99 keyed to the adjacentends of the shafts 6d and 88 respectively. While chains and sprocketshave been illustrated and described, obviously any suitable arrangementof gears yorotl'ier conventional transmissionl equipment may bev usedvwhichV will deliver driving power to the shafts 64 and 88 With adifferential action therebetween.

The dierential rmechanism 96 provides for differential speeds' ofrotation'ofV the shafts 64 and 88 and between the front `and rear axle,`thereby assuring proper driving*` contact withl the ground by eachwheelwhen `the-tractor'is `negotiating curves and the -meanspeed'ofrotationfof the front wheels is different thanthe mean-'speed ofL rota#tion-oith'evrear wheels. i

Therstructure thus Yfar described` provides for delivery of-` power fromthe engine to. eachx ofythel wheels' 7 ands for propellingthe-.vehicleeand ,I 94 iand- 'plates I |36I oni the --opposite `-sideLof saidaxle housing. The-feet [I4-fiere -secured to the axle housingadjacentthe wheels 1, thechannel members |92 and/|93 extendingforwardlyofethe axle and 'coni/erging;v ther free l--ends Abeing-conf nected lbyIsuitable plaes JI |11l Lor the likewelded thereon.- It ispreferable-that the t0ngue-struc ture-befrelativelystrong and theforward end f thereof provided with ya suitable -membern |98- forming aibumper which extends outwardlyviin- .gfront -of the wheels It ispreferable that the actual steering be -done 'bypower mecha-nismand inthe-illustrated structure-'the plate IIN-supports a balland socket joint|09 providing-a swivel connection with a cylindricalbar=||9-1extending=to @the rear ofthe ball andfsocket-joint androtatably and slidably mountedin-'asleeve III'. Secured`A tothelsidesVof thesleeve are upwardly'extending plates IIZ forming spaced earshaving bea-ring`V openings ||3 adapte'dtof-align withan'aperture-in .-II D therein about a horizontal axis formed by the pin I Il.

The `gear reduction-unit I I6 -maybe of any suitable'form butpreferably-is a'double wormlgear reduction and is supportedonea'suitable plate I I8 or the like having its ends-secured'toextensions II9 and |29 of the longitudinalframe'emembers 9 and |9 toprovide-a-rlgid, sturdysupport for thegear reduction unit. The use of adouble worm gear reduction unitprevents shocks onthewheels fromchangingthe"relative-position of theaxle housing 6 and the fram-e,whereby anyvchange of the-arcor turn ofthe vehiclefmust bein responsetopower appliedunder control-of the op erator. Power isappliedftothefinput shaft |2| of the gear reduction-unit,-said shaftbeingconv nected to an hydrau1icmotor-|22 supported by a suitablebracket |23 on the frame member-9. The hydraulic motor is connected toand has communication with tubes orducts |24 and |25 and is4soconstructed. that when fluid-is applied through one of thetubes thehydraulic motor rotatesftheshaft |2|' inione direction, and when fluidis i applied through the other -tube the-hydraulic motor rotates theshaft |2|` in the other direction-thereby providing a reversing driveVfor the gear reduction unit ||6.- Theoppositeends of` thetubes |24 and|25 are connected toa control valve |26-, said valvealso-havingconnection by means of a tube |21 to a-uid'reservoir |29 andby a tube |29 connected to thedischargeof an hydraulic pump |30;the-intake of said pump.: being connected by a tubeg|3|l `withthereservoir. |28.

The pump I 30 `is suitably secured-'tothe i frameA asaige engine 4, thepump preferably having a built-in bypass designed to open at apredetermined pressure. The pump draws fluid from the reservoir |28through the tube |3| and pumps said fluid through the tube |29 to thevalve |26, said valve being of conventional structure having two valveplungers which, when in neutral position, close all intake and outletports, the valve plungers being controlled by a lever |33 pivoted as at|34 on the valve body and having portions contacting the extending endsof the Valve plungers whereby movement of the lever |33 in an upwarddirection, as shown in Fig. 6, pushes one of the valve plungers inwardlyand allows the other to move outwardly, opening passages in the valvewhereby fluid from the pump flows from the tube |29 through the valveand through the tube |24 to the hydraulic motor |22 to revolve same in ayclockwise direction Fig. l, discharge from the motor |22 flowingthrough the tube |25, through the valve and tube |21 to the reservoir|28. Downward movement of the lever |33 reverses the position of thevalves whereby fluid flows from the tube |29, through the control valveand tube |25 to the hydraulic motor and the return from the motor passesthrough the tube |24, control valve and tube |21 to the reservoir |28.When the lever |33 is in neutral position, there is no rotation of theshaft V|2|'v by the motor |22 and the pressure in the line |29 is at thepredetermined amount to effect instantaneous starting of movement uponthe movement of the control lever |33.

The control valve |26 is suitably secured to the frame member 9 in aposition whereby the lever |33 extends forwardly thereof, the free endof the lever being secured as by welding to a Z-shaped member |35 havinga flange |33 connected by a link |31 to an arm |38 extending laterallyfrom a collar |39 on the lower end of a steering shaft rotatably mountedin the steering column |40, the other end of the shaft carrying theconventional steering wheel |4| adjacent the seat |42 for the operator,the column |40 being suitably secured in the instrument panel and to theframe to provide a rigid support for said column. The collar |39 isprovided with an arm |43 on the lower end thereof which preferablyextends downwardly and is connected to one end of an extension spring|44, the other end of said spring being connected to a suitable memberrigid on the frame whereby the spring tension tends to return the arm|43 to` a vertical position which corresponds to a neutral position ofthe lever |33 at any time when the operator is not applying rotativepressure to the steering wheel |4|.

In order to limit turning movement of the axle housing 5, the Z-member|35 has a downwardly turned flange |45 connected by links |46 with aplate |41 rotatably mounted on a shaft |48, said shaft |48 being xed ona bracket |48 which is suitably secured to the frame member 9. The plate|41 is preferably substantially a quarter of a circle and forms a bellcrank by having the links |46 connected adjacent its periphery at oneend and a yoke |49 pivotally and loosely connected to the opposite endwhereby lines through the pivotal connections of the 'plate |41 formsubstantially a right angle at the axis of the shaft |48. Secured to theyoke |49 is a shaft |50 extending through and loosely slidable in anaperture of an ear |52 mounted for rotation about a vertical axis on aflange |53 or other support -on the A-frame member CTI l1. .The movementof the ear |52 toward and away from the longitudinal center of thevehicle in responsev to turning movement of the axle housing 5 isrelatively small whereby the loose nt of the shaft |50 in the aperture|5| and the loose connection of the yoke |49 prevent binding of saidshaft. Secured to the shaft |50 on opposite sides of the ear |52 arecollars |54 and |55 so positioned that when the axle is turning andapproaching a desired limit the ear |52 engages the respective collarapplying force to the shaft |50 to move the plate |41 and return thelever |33 to the neutral position, this force overpowering any force theoperator might apply to the steering wheel |4| tending to continue tohold the lever |33 in position to effect the turning operation. Forexample, when the pump |30 is operated and the steering wheel turned tomove the lever |33 upwardly, Fig. 6, causing the fluid to drive themotor |22 and turn the axle to the right, Fig. 2, the ear |52 approachesthe collar |54. Before the axle is turned to a predetermined limit theear |52 engages the collar |54 and continued turning of said axle causesthe collar |54 to move with the axle and ear |52, pulling the shaft |50.The force on the shaft |50 overpowers the force the operator applies tothe steering wheel whereby the plate |41 is rotated drawing the lever|33 downwardly to neutral position stopping operation of the motor |22and holding the axle turned to the right to the limit of its movementuntil the steering wheel is turned to move the lever |33 downwardly forturning the axle to the left.

In operating a device constructed as described the engine 4 is startedas in conventional motorized equipment, the clutch pedal |56 operated,the gear shift lever |51 moved to place the power transmission equipmentin the proper gear and the clutch pedal let out to engage the clutch asin conventional practice. The power of the engine is delivered throughthe transmission mechanism in the housing 66 to rotate the sprocket 89which through chain 90 drives the sprocket 9|, rotating the differentialmechanism 96. The pinion 98 and beveled gears 99 and |00 transmit therotation of the differential mechanism and effect differential rotationof the shafts 64 and 88 respectively, thereby driving the drivey shafts6| ad 86 to transmit propelling power through the gearing in thehousings 53 and 82 and Vdifferential gearing in the housings 44 and 80to deliver propelling power to the wheels 1 and 8. Through thisarrangement power is applied to each of the wheels, making anall wheeldrive vehicle which will maintain ground engagement by the wheels whennegotiating turns in which each wheel rotates at a different speed dueto the different radii of the circles in which the wheels move.

In forward movement of the vehicle over irregular terrain, differentrelative vertical positions of the rear wheels effect tilting of theframe as the rear axle housing 6 is rigid therewith. The front wheels,however, assume different relative heights without tilting of the framesdue to the pivotal connection or oscillation of the plates 30 and 3|carrying the rollers 26 and 21 for stabilizing the arcuate member 23.Therefore the front axle housing 5 may swing about the ball and socketmembers |3 and |4 in a vertical plane transversely with the longitudinalcenter of the vehicle and the collar 14, being rotatable f and slidableon the shaft 15. maintains the alignment-fofl'fthe gear housing53-fwhile--fpermitting Ysuch Iswinging. motion.-

While the engine 4l Ais* operating it' is Iconstantly `driving :thepumpA |30- drawing hydraulic 'Huid `from theA lreservoir |28 throughlthe tube I 3| and r-maintaining av predetermined pressure las determinedby the bypass arrangement in the pump. When it'isdesired to turn thevehicle the steering wheel I4I may be turned, `for example, to the left,moving the arm |38 downwardly and through the -link |31' and Z-member I35 moves the lever I 33 `downwardlyon lthe pivot -I34ito movethevalveplungers to permit passage of ufluid from 'the pump rthrough the tube|29, valve body |26,` the tube 25 to the hydraulic motor |22, 'thedischarge from said vmotor re- -turning through the'tube |24, throughthevalve body |26, tube |21 tothe Areservoir |23.l The movement of the'hydraulic 'fluid through the motor |22 effects rotation of ythe shaftAv|2I to drivethe gearsin the' gear reduction unit LI||i vto reffect arelatively slow, positive -turning of'the shaft I |5 to positivel'yturnVthe sleeve bar I l :and through the ballfand socket joint |09 `move thetongue |01 to the left, turning the ment of the steering wheel and thelever |33" moves "the plate I4I on itsv pivot shaft |48 Vto shift theshaft |50 forwardly-through 'the-aperture I5| in the ear |52. `It ispreferable -that the valve Abody I 26V and plungers therein be soarranged with taperedV portions plungers cooperating with thefopenings*for-,passage of the iluidthrough the valve bodywhereby nflow ofv fluidto the motorwill increase in proportion tothe-amount of rotationf'oftheisteering wheel '|4`I, the greater the movement' of the "ilwheel-'|41 'from neutral position', the greaterthe amountofuidfdelivered to the'motor |22. This provides a variable control overthe speed of turning movement delivered by the speed reduction unit IIB,however, as long as turning pressure is applied to the steering wheel tohold same out of neutral position, turning movement of the axle housing5 will continue until the ear |52 contacts the collar I 55 and then continued movement of the axle applies pressure to the collar |55 to pivotthe plate |41 and apply pressure to the arm |33 to return same to aneutral position, this pressure overcoming the pressure applied to thesteering wheel by the operator.

Rotation of the steering wheel I4| to the right moves the lever |38upwardly to effect upward movement of the lever I 33 to move the valveplungers in the valve body |26 whereby fluid may flow from the pumpthrough the tube |29, valve body |25, tube |24, to the motor |22, thereturn of the fluid being through the tube |25, valve body |25, tube |21to the reservoir |28. This effects a reverse movement through the motor|22 to drive the shaft |2I and effect turning of the shaft II5 to turnthe sleeve III and ball |09 to the right, drawing the tongue IDI to theright to swing the axle housing 5 about the vertical axis through theball and socket members I3 and I4. This turning movement `willv.continue as long` als-pressure is applied to the steering wheel |4I,and when suchpressure is released tension-of the spring |44 pulls thearm |43 to a vertical position returning the `steering wheel and alsovthe valve members in the valve body |26 jto neutral position wherebyall liow to and from the hydraulic motor |22 is stopped. This leavesthe-axlev housing 5 inv the same position as itrwas `when the steeringwheel was released. The vehicle will continue on the same course until`the--steering wheel |4'I `is again moved as the double gear reductionin the unit I Iprevents any-shocks on either of the wheels 'i fromeffecting anyturning movement of the/axle housing 5.

The power for this-'steering is in the hydraulic mechanism and gearreduction, thereby requiring very little effort on the part of thedriver to steer the vehicle, and if desired suitable indicators may beprovided to indicate the speed at which the axle housing -5f`is beingturned and also the relative angular-direction of said axle housing andframe. The power turning of the axle housing 5permits the vehicle tonegotiate a curve of very shortradius and also permitsthe front axle tobe turned while the vehicle is stationary as when making a sharp turnaty the corner of a field.

It is believedobvious that I have provided a motorized vehicle having `amultiple number of axles in which all of thewheels are driven and inwhich one .of the axles is steered with an ease ofr control on all typesof terrain providing a flexibilityA of operation inta high tractionVehicle.

What I claim anddesire to secure by Letters Patent is:` Y

,1. A power steering mechanism for turning an axle of a motor vehiclehaving av chasis and said axle mounted on the chassis in spaced relationthereto for swinging and turning movement comprising, agear reductionYunit having a driving shaft anda vertically disposed' driven shaft andmounted on the chassis with said driven shaft Vspaced from the axlemounting, telescoping means having one portion pivotally lmounted onsaid driven shaft, means connecting the other portion of Athetelescoping means to'theaxlein spaced relation-tothe axle mounting,power means on the chassis and operatively connected to the drivingshaft of the gear reduction unit for rotating the drive shaft thereof toswing the telescoping means and effect turning movement of the axle, andmeans on said chassis for controlling the direction and speed ofoperating of said power means.

.2. A power steering mechanism for turning an axle of a motor vehiclehaving a chassis and said axle universally mounted on the chassis inspaced relation thereto for swinging and turning movement comprising, auniversal joint connected with the axle`in spaced relation to theuniversal mounting of said axle, a gear reduction unit having a drivingshaft and a vertically disposed driven shaft and mounted on the chassis.with said driven shaft spaced between the universal mounting of saidaxle and the universal joint, telescoping means having one portionpivotally mounted on said driven shaft and the other portion connectedwith the universal joint, power means on the chassis and operativelyconnected to the driving shaft of the gear reduction unit for rotatingthe drive shaft thereof to swing the telescoping means and effectturning movement of the axle housing, and means on said chassis forcontrolling the direction and speed of operation of said power means.

3. A power steering mechanism for turning an axle of a motor vehiclehaving a chassis and said axle universally mounted on the chassis inspaced relation thereto for supported swinging and turning movementcomprising, a universal joint connected with the axle in spaced relationto the universal mounting of said axle, a power shaft mounted on thechassis for rotation about a vertical axis between the universal jointand the universal mounting of the axle, telescoping means having oneportion pivoted on the power shaft and the other portion connected withthe universal joint, a motor on the chassis, a speed reducing mechanismon said chassis operatively connecting the motor and power shaft, andmeans onsaid chassis for controlling operation of the motor anddirection of rotation thereof in driving the power shaft to effectcontrolled directional turning of the axle.

4. A power steering mechanism for turning an axle of a motor vehiclehaving a chassis and said axle universally mounted on the chassis inspaced relation thereto for supported swinging and turning movementcomprising, a universal joint connected with the axle in spaced relationto the universal mounting of said axle, a power shaft mounted on thechassis for rotation about a vertical axis between the universal jointand the universal mounting of the axle, telescoping means having oneportion pivoted on the power shaft and the other portion connected withthe universal joint, a fiuid motor on said chassis. a speed reducingmechanism on said chassis operatively connecting the uid motor and powershaft, a source of iiuid pressure, a valve on said chassis forcontrolling application of the fluid pressure to the uid motor tothereby alter the direction of rotation of said motor whereby controlleddirectional turning of the axle is effected, and means on said chassisfor actuating the valve to stop operation of the motor in response toturning of the axle to a predetermined limit. I

5. A power steering mechanism for turning an axle of a motor vehiclehaving a chassis and said axle universally mounted on the chassis forswinging and turning movement about the axis through the universalmounting comprising, a gear reduction unit having a driving shaft and avertically disposed driven shaft and mounted on the chassis with saiddriven shaft spaced from the universal mounting of the axle, telescopingmeans having one portion hinged on said driven shaft, means universallyconnecting the other portion of the telescoping means with theaxle inspaced relation to the axes of the driven shaft and the universalmounting of the axle whereby turning of the driven shaft turns the axleabout an axis extending through the universal mounting of the axle, anhydraulic motor on said chassis and operatively connected to the drivingshaft of the gear reduction unit for rotating the driven shaft thereofto swing the telescoping means and effect turning movement of the axle,a -pump on said chassis for supplying fluid under pressure, means onsaid chassis for controlling the application of uid pressure to thehydraulic motor and thereby effecting the directionof rotation of saidmotor whereby the direction of turning of the axle is controlled, andlimit means associated with and operating in response to turning of theaxle for stopping operation of the motor.

FRED P. MARTIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 810,261 l Cantelou Jan. 16, 1906885,014 Brightmore Apr. 21, 1908 1,076,052 Morton Oct. 21, 19131,274,434` Morton Aug. 6, 1918 1,323,890 Manly Dec. 2, 1919 1,371,641Morton Mar. 15, 1921 1,376,286 Lingard Apr. 26, 1921 1,447,073 Gore Feb.27, 1923 1,457,692 Carter June 5, 1923 2,268,465 Townsend Dec. 30, 19412,308,351 Blagden et al Jan. 12, 1943 2,464,110 Wright Mar. 8, 1949

